String-plate for pianos.



E. J. KNABE, JR. STRING PLATE FOR PIANOS.

APPLIOATION FILED JUNE 1, 1911.

1,008, 1 61. Pat gnted Nov. 7, 1911.

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ERNEST J. KNABE, JR.,

OF CINCINNATI, OHIO.

STRING-PLATE FOR PIANOS.

Application filed June 1, 1911.

Specification of Letters Patent.

Patented Nov. *7, 1911.

Serial No. 630,718.

T 0 all whom it may concern:

Be it known that I, ERNEST J. KNABE, Jr., a citizen of the UnitedStates, residing at Cincinnati, in the county of Hamilton and State ofOhio, have invented certain new and useful Improvements in String-Platesfor Pianos; and I do hereby declare the following to be a full, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

The present invention relates to string plates or frames for pianos andproposes a construction of plate which is considerably lighter than thesame type of plate now being used, and which has its maximum strength atthat part which is subjected to the greatest strain; one which willefiectively resist the strain or pull of the strings; and wherein afuller and freer course is afforded for the sound waves than is nowobtained.

To these ends the invention consists in the novel combinations of partsand details of construction more fully hereinafter disclosed andparticularly pointed out in the claims.

Referring to the accompanying drawings forming a part of thisspecification and in which like numerals designate like parts in all theviews :Figure 1 is a front elevation of the plate. Fig. 2 is a crosssectional view thereof taken on the line 22 of Fig. 1; and, Fig. 3 is asimilar sectional view taken on the line 3-8 of Fig. 1.

The plate consists of an upper section 1, a lower section 2, and anintermediate or central section 3; said upper and central sections beingunited by the pair of parallel ribs 4 and 5 on one side, and by twodiagonally crossed ribs 6 and 7 on the other side thereof; and the lowersection 2 is united to the central section 3 by continuations of saidribs 5 and 6.

The upper section 1 is reinforced by two substantially parallel andlongitudinally disposed ribs 8 and 9 the former of which is locatedalong the marginal edge of said section and the latter is in the bodythereof. The ribs 4 and 10 located on the marginal side edges of saidupper section serve as transverse reinforcements for said section. Thereinforced construction of the section 1 as just described is of knownconstruction.

The central section 3 has one edge thereof constructed with a relativelywide rib 11 to which are secured the hitch pins 12 for the strings whichstrings are secured at their other ends and in the usual manner to thewrest plank that is fastened to the back of the section 1.

All string plates are fastened at the top and any movement of the plateitself, which may result from the strain of the strings is confined tothe lower part of the plate and to that part to which the hitch pins areattached, and to equalize or resist this the central section 3 isreinforced by continuous ribs on directly opposite sides thereof. Eachof said ribs consists of a series of similar trussed sections 13 13 and13 formed integral with the plate section 3 and located in oppositepairs between each two adjacent ribs (4;, 5, 6 and 7). The salient pointof each of the truss sections is located at substantially the middlepoint between each two ribs (see Fig. 3) the purpose of which will bereadily understood. The intermediate plate section 3 is constructed withintegral and triangular-like truss sections 1 1 14 and 14 for each ofthe opposed pairs of truss members 13, said truss members 14 1 1 and 14*being disposed at right angles to the truss members 13, 18 and 13 andhave their apices at the points of greatest strain of the strings.

By the construction and design of plate disclosed herein a much lighterplate is obtained; and one having a considerably greater cross sectionalopening in front of the sounding board for the same given size of platethan heretofore, resulting in a fuller and freer course for the soundwaves.

It is obvious that those skilled in the art may vary the details ofconstruction and arrangement of parts without departing from the spiritof my invention, and therefore I do not wish to be limited to suchfeatures except as may be required by the claims.

What I claim is 1. A string-plate for pianos comprising end sections anda central section united by ribs disposed transversely of the plate; andreinforcing ribs formed integral with said central section, said ribsdisposed lengthwise of the central section and located on opposite sidesthereof, substantially as described.

2. A string-plate for pianos comprising end sections and a centralsection united by ribs disposed transversely of the plate; andreinforcing ribs for said central section, said reinforcing ribsdisposed on the opposite faces and lengthwise of the central section,

and increasing in depth to either side of said transverse ribs,substantially as described.

3. A string-plate for pianos comprising end sections, and a centralsection; ribs disposed transversely of the plate and uniting saidsections; and ribs formed integrally with and on the opposite sides ofthe central section and reinforcing the same, said ribs comprising aseries of truss members each located between and disposed transverselyof the first-named ribs, substantially as described.

4. A string plate for upright pianos, comprising an upper, lower, andcentral section; ribs disposed transversely of the plate and unitingsaid sections; ribs integral with and on the opposite sides of thecentral section reinforcing the same, said ribs comprising a series oftruss members disposed in opposed pairs transversely of the first namedrib; and a truss member for each pair of ribs formed integral with saidcentral section adapted to resist the strain of the strings,substantially as described.

In testimony whereof, I affix my signature, in presence of twowitnesses.

ERNEST J. KNABE, JR. Witnesses:

E. A. DOLL, JOHN H. AYDnLoTT.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

